$element-separator:        "__" !default;
$modifier-separator:       "--" !default;
@mixin b($name) {
  .#{$cls-prefixs}#{$name}-g {
    @content;
  }
}
@mixin e($name) {
  @at-root {
    &#{$element-separator}#{$name} {
      @content;
    }
  }
}
@mixin m($name) {
  @at-root {
    &#{$modifier-separator}#{$name} {
      @content;
    }
  }
}
